1. Field of the Invention
The present invention relates, in general, to coffee makers. More specifically, the invention relates to a coffee maker of the so called syphon-type, which includes a lower receptacle containing water and an upper receptacle containing ground coffee. The upper receptacle is arranged on the lower receptacle for fluid communication therebetween.
2. Description of the Prior Art
Syphon-type coffee makers, as shown in FIG. 1, have been used widely, in particular, among frequent coffee drinkers. A typical syphon-type coffee maker 1 includes upper and lower receptacles 3 and 5 and heater 7. A water conducting tube 9 projects outward from the bottom surface of upper receptacle 3. A filter 11 is detachably arranged on the bottom of upper receptacle 3 by a coil-spring 13 positioned in water conducting tube 9. One end of coil-spring 13 is fixed to the center of filter 11 and the other end thereof is hooked at the edge of water conducting tube 9. A supporting member 15 includes an arc-shaped pedestal 17, a handle portion 19 extending perpendicularly from the center of pedestal 17 and a holding member 21 extending at a right angle from the top of handle portion 19. A U-shaped grip member 23 is formed at the top of holding member 21 to grip lower receptacle 5 by its U-shaped portion. A lid 25 is detachably arranged on the opening of upper receptacle 3.
When using the above-described coffee maker, ground coffee is put into upper receptacle 3 and a proper amount of water corresponding to the amount of coffee is stored in lower receptacle 5. Upper receptacle 3 is firmly fixed on lower receptacle 5 so that it communicates with the interior of lower receptacle 5 through water conducting tube 9 and filter 11. The upper and lower receptacles 3 and 5 are supported by supporting member 15, and heater 7 is positioned under lower receptacle 5 to heat the water in lower receptacle 5. When the water is boiled by heater 7, the vapor pressure in lower receptacle 5 rises gradually due to an increase in vapor within lower receptacle 5. The boiled water in lower receptacle 5 is transferred to upper receptacle 3 by the increased vapor pressure through water conducting tube 9 when the vapor pressure in lower receptacle 5 exceeds a prescribed value. Therefore, the groung coffee in upper receptacle 3 is mixed with the boiled water. After that, heater 7 is removed from the position under lower receptacle 5, and lower receptacle 5 cools. Consequently, the vapor pressure in lower receptacle 5 falls, thus producing a partial vacuum in lower receptacle 5. The partial vacuum causes the coffee liquid mixture in upper receptacle 3 to pass from upper receptacle 3 into lower receptacle 5 through filter 11 and water conducting tube 9.
In this conventional coffee maker, since heater 7 is separated from the other components, users have to handle heater 7 and the other components separately when using the coffee maker, causing inconvenience. Furthermore, the heater 7 may become lost or misplaced, unless stored with the other components.
To solve the problems described above, the separate heater 7 may be integrally mounted on a base member. However, if the separate heater 7 is integrally mounted on the base member, as described above, it is difficult to rapidly cool lower receptacle 5 after the water in lower receptacle 5 passes to upper receptacle 3. This is because heater 7 cannot be moved from the position under lower receptacle 5. Even though the power supplied to heater 7 is cut off, residual heat is still radiated from heater 7 for a certain period of time. Thus, lower receptacle 5 does not cool quickly. As a result, the coffee liquid in upper receptacle 3 is not quickly transferred into lower receptacle 5, thus causing deterioration of the quality of the resulting coffee.